Bidirectional optical transmission system for dense interleaved wavelen gth division multiplexing

摘要

An optical fiber amplifier and filtering apparatus and method for a bidirectiona l wavelength-division-multiplexing (WDM) system having odd and even interleaved channels is disclosed. The apparatus uses optical circulators, in-fiber Bragg gratings, and erbium-doped fiber amplifiers to amplify channels traveling in opp osite directions in a WDM system and to filter unwanted ASE and back reflection noise between the channels. Interface circulators positioned at opposite ends of the apparatus respectively receive odd and even channels traveling in opposite directions in the WDM system and pass the channels through an erbium-doped fiber amplifier. Other circulators direct the amplified channels to two series of Brag g gratings that respectively reflect only the odd channels and pass only the even channels or vice versa, thereby filtering ASE and other noise located between th e channels. An additional amplifier may boost the channels before they exit the apparatus via the interface circulators.